Armchair



FIG. 1 is a front isometric view of an armchair showing my new design;

FIG. 2 is a side elevational view taken from the right of FIG. 1, the side opposite being similar;

FIG. 3 is a rear elevational view;

FIG. 4 is a front elevational view;

FIG. 5 is a bottom view. 

The ornamental design for an armchair, substantially as shown and described. 